UE Capability-Based CSI Report Configuration

ABSTRACT

A user equipment (UE) is configured to report capabilities to as network. The UE transmits UE capabilities for channel state information (CSI) reporting to a base station, wherein the UE capabilities include a CSI-RS-resource-indicator(CRI)-rank indicator(RI)-channel quality indicator (CQI) reporting capability and a further CRI-RI-CQI reporting capability and receives a CSI report configuration from the base station, wherein the CSI report configuration is based on the UE capabilities.

BACKGROUND

In 5G new radio (NR) wireless communications, the 5G NR network mayassign one or more frequency sub-bands to a user equipment (UE) toexchange information with the network. These sub-bands are allocated tothe UE based on measured channel conditions that the UE reports to anext generation NodeB (gNB) of the network based on channel stateinformation (CSI) measurements conducted by the UE on a CSI referencesignal (CSI-RS). Two categories of CSI reports are link adaptation (LA)CSI reports that primarily focus on digital precoding, and beammanagement (BM) CSI reports that primarily focus on analog precoding.There are currently six codebook types for LA CSI reports: (1)Release-15 (Rel-15) Type I Single Panel, (2) Rel-15 Type I Multi-Panel,(3) Rel-15 Type II, (4) Rel-15 Type II Port Selection, (5) Rel-16enhanced Type (eType) II, and (6) Rel-16 eType II Port Selection. Inaddition, LA CSI reports also include CSI-RS resource indicator-rankindicator-channel quality indicator (cri-RI-CQI) reports.

SUMMARY

Some exemplary embodiments are related to a processor configured toperform operations. The operations include transmitting UE capabilitiesfor channel state information (CSI) reporting to a base station, whereinthe UE capabilities include a CSI-RS-resource-indicator(CRI)-rankindicator(RI)-channel quality indicator (CQI) reporting capability and afurther CRI-RI-CQI reporting capability and receiving a CSI reportconfiguration from the base station, wherein the CSI reportconfiguration is based on the UE capabilities.

Other exemplary embodiments are related to a processor configured toperform operations. The operations include entering a discontinuousreception (DRX) active time period, determining whether channel stateinformation (CSI) resources were received during the DRX active timeperiod and when CSI resources were received during the DRX active timeperiod, determining whether to perform CSI measurements during the DRXactive time period based on the received CSI resources.

Still further exemplary embodiments are related to a processorconfigured to perform operations. The operations include receiving oneof a first restriction from a base station regarding a precoding matrixindicator (PMI) codebook rank or a second restriction from the basestation regarding one or more PMI codebook values and reporting a PMIvalue to the base station based on at least one of the first restrictionor the second restriction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary network arrangement according to variousexemplary embodiments.

FIG. 2 shows an exemplary UE according to various exemplary embodiments.

FIG. 3 shows an exemplary base station configured to establish aconnection with a user equipment according to various exemplaryembodiments.

FIG. 4 shows a method of reporting the CSI capability of a UE accordingto various exemplary embodiments.

FIGS. 5A-5C shows exemplary diagrams illustrating reception of CSIresources in the time domain according to various exemplary embodiments.

DETAILED DESCRIPTION

The exemplary embodiments may be further understood with reference tothe following description and the related appended drawings, whereinlike elements are provided with the same reference numerals. Theexemplary embodiments describe a device, system and method for a nextgeneration NodeB (gNB) of a 5G new radio (NR) network to configure a CSIreport configuration based on a user equipment (UE) capability reportedby the UE.

The exemplary embodiments are described with regard to a network thatincludes 5G new radio NR radio access technology (RAT). However, theexemplary embodiments may be implemented in other types of networksusing the principles described herein.

The exemplary embodiments are also described with regard to a UE.However, the use of a UE is merely for illustrative purposes. Theexemplary embodiments may be utilized with any electronic component thatmay establish a connection with a network and is configured with thehardware, software, and/or firmware to exchange information and datawith the network. Therefore, the UE as described herein is used torepresent any electronic component.

As noted above, one type of CSI report is the cri-RI-CQI report. Thereare two categories of cri-RI-CQI reports. The first is the cri-RI-CQIreport with non-PMI-PortIndication and the second is the cri-RI-CQIreport without non-PMI-PortIndication. These two categories ofcri-RI-CQI reports are defined in 3GPP technical specification (TS)38.214 section 5.2.1.4.2. The cri-RI-CQI with non-PMI-PortIndication mayprovide the gNB with more flexibility in terms of configuring the portcombination that the UE can report. However, processing this reportrequires significantly more memory at the UE than the cri-RI-CQI withoutnon-PMI-PortIndication report because when non-PMI-PortIndication isconfigured, the port selection for every rank is configured by the gNBfor each resource. In current 5G NR networks, if the UE supportscri-RI-CQI reporting, then the UE must support both types of cri-RI-CQIreporting. It would be beneficial to reduce the memory requirements atthe UE side while maintaining the UE's capability to support cri-RI-CQIreporting.

According to some exemplary embodiments, when the UE reports support forcri-RI-CQI reporting, the UE additionally indicates whether or notnon-PMI-PortIndication based cri-RI-CQI reporting is supported. As such,the UE may indicate support for the less memory-intensive cri-RI-CQIwithout non-PMI-PortIndication report but not the cri-RI-CQI withnon-PMI-PortIndication report.

Two types of resources configured by the gNB for UE measurement for aCSI report are the channel measurement resources (CMR) and interferencemeasurement resources (IMR). When the power saving connected modediscontinuous reception (CDRX) is configured for a UE, the UE mayreceive the CMR or IMR during one DRX active time period and the otherof the CMR or IMR during another active DRX time period. The result ofthis behavior is that the UE will store the CMR or IMR measurements fromthe first active DRX time period until it receives and performs themeasurements with the other during another active DRX time period. Assuch, memory at the UE is not being utilized efficiently.

According to some exemplary embodiments, the UE is not expected tohandle the above-mentioned scenario in which the UE receives the CMR inone active DRX time period and the IMR in another active DRX timeperiod. Instead, the UE may report the CSI based on measurements duringa DRX active time period in which both the CMR and IMR have both beenreceived.

In current 5G NR network design, for Type I codebook with twotransmission antenna ports at the gNB (2 port NZP-CSI-RS as CMR), thegNB may configure both a twoTX-CodebookSubsetRestriction, as defined in3GPP TS 38.214, and a typeI-SinglePanel-ri-Restriction, as defined in3GPP TS 38.331, to restrict which precoding matrix indicator (PMI) canbe selected by the UE from the Rel-15 Type I Single Panel codebookdefined in 3GPP TS 38.214. However, there are scenarios when these tworestriction methods may conflict.

According to some exemplary embodiments, when the gNB configures boththe twoTXCodebookSubsetRestriction and thetypeI-SinglePanel-ri-Restriction, the UE may either ignore one of thesemethods or may honor both restrictions in case a conflict arises.

FIG. 1 shows an exemplary network arrangement 100 according to variousexemplary embodiments. The exemplary network arrangement 100 includes aUE 110. It should be noted that any number of UEs may be used in thenetwork arrangement 100. Those skilled in the art will understand thatthe UE 110 may alternatively be any type of electronic component that isconfigured to communicate via a network, e.g., mobile phones, tabletcomputers, desktop computers, smartphones, phablets, embedded devices,wearables, Internet of Things (IoT) devices, etc. It should also beunderstood that an actual network arrangement may include any number ofUEs being used by any number of users. Thus, the example of a single UE110 is merely provided for illustrative purposes.

The UE 110 may be configured to communicate with one or more networks.In the example of the network configuration 100, the networks with whichthe UE 110 may wirelessly communicate are a 5G New Radio (NR) radioaccess network (5G NR-RAN) 120, an LTE radio access network (LTE-RAN)122 and a wireless local access network (WLAN) 124. However, it shouldbe understood that the UE 110 may also communicate with other types ofnetworks and the UE 110 may also communicate with networks over a wiredconnection. Therefore, the UE 110 may include a 5G NR chipset tocommunicate with the 5G NR-RAN 120, an LTE chipset to communicate withthe LTE-RAN 122 and an ISM chipset to communicate with the WLAN 124.

The 5G NR-RAN 120 and the LTE-RAN 122 may be portions of cellularnetworks that may be deployed by cellular providers (e.g., Verizon,AT&T, Sprint, T-Mobile, etc.). These networks 120, 122 may include, forexample, cells or base stations (Node Bs, eNodeBs, HeNBs, eNBS, gNBs,gNodeBs, macrocells, microcells, small cells, femtocells, etc.) that areconfigured to send and receive traffic from UE that are equipped withthe appropriate cellular chip set. The WLAN 124 may include any type ofwireless local area network (WiFi, Hot Spot, IEEE 802.11x networks,etc.).

The UE 110 may connect to the 5G NR-RAN 120 via the gNB 120A and/or thegNB 120B. During operation, the UE 110 may be within range of aplurality of gNBs. Thus, either simultaneously or alternatively, the UE110 may connect to the 5G NR-RAN 120 via the gNBs 120A and 120B.Further, the UE 110 may communicate with the eNB 122A of the LTE-RAN 122to transmit and receive control information used for downlink and/oruplink synchronization with respect to the 5G NR-RAN 120 connection.

Those skilled in the art will understand that any association proceduremay be performed for the UE 110 to connect to the 5G NR-RAN 120. Forexample, as discussed above, the 5G NR-RAN 120 may be associated with aparticular cellular provider where the UE 110 and/or the user thereofhas a contract and credential information (e.g., stored on a SIM card).Upon detecting the presence of the 5G NR-RAN 120, the UE 110 maytransmit the corresponding credential information to associate with the5G NR-RAN 120. More specifically, the UE 110 may associate with aspecific base station (e.g., the gNB 120A of the 5G NR-RAN 120).

In addition to the networks 120, 122 and 124 the network arrangement 100also includes a cellular core network 130, the Internet 140, an IPMultimedia Subsystem (IMS) 150, and a network services backbone 160. Thecellular core network 130 may be considered to be the interconnected setof components that manages the operation and traffic of the cellularnetwork, e.g. the 5GC for NR. The cellular core network 130 also managesthe traffic that flows between the cellular network and the

Internet 140.

The IMS 150 may be generally described as an architecture for deliveringmultimedia services to the UE 110 using the IP protocol. The IMS 150 maycommunicate with the cellular core network 130 and the Internet 140 toprovide the multimedia services to the UE 110. The network servicesbackbone 160 is in communication either directly or indirectly with theInternet 140 and the cellular core network 130. The network servicesbackbone 160 may be generally described as a set of components (e.g.,servers, network storage arrangements, etc.) that implement a suite ofservices that may be used to extend the functionalities of the UE 110 incommunication with the various networks.

FIG. 2 shows an exemplary UE 110 according to various exemplaryembodiments. The UE 110 will be described with regard to the networkarrangement 100 of FIG. 1. The UE 110 may represent any electronicdevice and may include a processor 205, a memory arrangement 210, adisplay device 215, an input/output (I/O) device 220, a transceiver 225and other components 230. The other components 230 may include, forexample, an audio input device, an audio output device, a battery thatprovides a limited power supply, a data acquisition device, ports toelectrically connect the UE 110 to other electronic devices, one or moreantenna panels, etc. For example, the UE 110 may be coupled to anindustrial device via one or more ports.

The processor 205 may be configured to execute a plurality of engines ofthe UE 110. For example, the engines may include a CSI management engine235. The CSI management engine 235 may perform various operationsrelated to reporting CSI capabilities of the UE 110 to the gNB 120 a,processing CSI reports, and handling conflicts arising from PMI and rankrestrictions. Examples of these processes will be described in greaterdetail below.

The above referenced engine being an application (e.g., a program)executed by the processor 205 is only exemplary. The functionalityassociated with the engine may also be represented as a separateincorporated component of the UE 110 or may be a modular componentcoupled to the UE 110, e.g., an integrated circuit with or withoutfirmware. For example, the integrated circuit may include inputcircuitry to receive signals and processing circuitry to process thesignals and other information. The engines may also be embodied as oneapplication or separate applications. In addition, in some UE, thefunctionality described for the processor 205 is split among two or moreprocessors such as a baseband processor and an applications processor.The exemplary embodiments may be implemented in any of these or otherconfigurations of a UE.

The memory arrangement 210 may be a hardware component configured tostore data related to operations performed by the UE 110. The displaydevice 215 may be a hardware component configured to show data to a userwhile the I/O device 220 may be a hardware component that enables theuser to enter inputs. The display device 215 and the I/O device 220 maybe separate components or integrated together such as a touchscreen. Thetransceiver 225 may be a hardware component configured to establish aconnection with the 5G NR-RAN 120, the LTE-RAN 122, the WLAN 124, etc.Accordingly, the transceiver 225 may operate on a variety of differentfrequencies or channels (e.g., set of consecutive frequencies).

FIG. 3 shows an exemplary network cell, in this case gNB 120A, accordingto various exemplary embodiments. The gNB 120A may represent any accessnode of the 5G NR network through which the UEs 110 may establish aconnection. The gNB 120A illustrated in FIG. 3 may also represent thegNB 120B.

The gNB 120A may include a processor 305, a memory arrangement 310, aninput/output (I/O) device 320, a transceiver 325, and other components330. The other components 330 may include, for example, a power supply,a data acquisition device, ports to electrically connect the gNB 120A toother electronic devices, etc.

The processor 305 may be configured to execute a plurality of engines ofthe gNB 120A. For example, the engines may include a CSI managementengine 335 for performing operations including configuring CSI reportsfor the UE 110 based on feedback from the UE 110. Examples of thisprocess will be described in greater detail below.

The above noted engine being an application (e.g., a program) executedby the processor 305 is only exemplary. The functionality associatedwith the engines may also be represented as a separate incorporatedcomponent of the gNB 120A or may be a modular component coupled to thegNB 120A, e.g., an integrated circuit with or without firmware. Forexample, the integrated circuit may include input circuitry to receivesignals and processing circuitry to process the signals and otherinformation. In addition, in some gNBs, the functionality described forthe processor 305 is split among a plurality of processors (e.g., abaseband processor, an applications processor, etc.). The exemplaryaspects may be implemented in any of these or other configurations of agNB.

The memory 310 may be a hardware component configured to store datarelated to operations performed by the UEs 110, 112. The I/O device 320may be a hardware component or ports that enable a user to interact withthe gNB 120A. The transceiver 325 may be a hardware component configuredto exchange data with the UE 110 and any other UE in the system 100. Thetransceiver 325 may operate on a variety of different frequencies orchannels (e.g., set of consecutive frequencies). Therefore, thetransceiver 325 may include one or more components (e.g., radios) toenable the data exchange with the various networks and UEs.

FIG. 4 shows a method 400 of reporting the CSI capability of the UE 110according to various exemplary embodiments. At 405, the UE 110 transmitsits cri-RI-CQI capability. In some embodiments, this capability includestwo parameters. The first parameter is whether or not the UE 110supports cri-RI-CQI reporting. If the UE 110 supports cri-RI-CQIreporting, the second parameter is whether or not the UE 110additionally supports cri-RI-CQI with non-PMI-PortIndication reporting.

In some embodiments, if the UE 110 does not support cri-RI-CQI withnon-PMI-PortIndication reporting, then to avoid a non-backwardscompatibility (NBC) issue, the capability reporting of the UE 110 ismodified to include a new csi-ReportWithoutPMI-r16 information element(IE) in addition to the existing csi-ReportWithoutPMI IE. The existingIE (csi-ReportWithoutPMI) indicates whether the UE 110 supports bothtypes of cri-RI-CQI reporting (with or without non-PMI-PortIndication)to existing networks (Rel-15 networks). The newly added IE(csi-ReportWithoutPMI-r16) introduces the concept of not supportingcri-RI-CQI with non-PMI-PortIndication reporting but supportingcri-RI-CQI without non-PMI-PortIndication). As a result, if a UE 110does not support cri-RI-CQI with non-PMI-PortIndication, the UE 110would set the existing csi-ReportWithoutPMI IE to 0 since existingnetworks do not support the scenario where the UE 110 supports one typeof report and not the other type of report. In contrast, for newernetworks (Rel-16 networks), the UE 110 would set thecsi-ReportWithoutPMI IE to 0 and the csi-ReportWithoutPMI-r16 IE to 1 toindicate that the UE 110 supports cri-RI-CQI withoutnon-PMI-PortIndication. Additionally, another UE capability may beintroduced for the UE 110 to indicate to the newer networks (e.g.,Rel-16 networks), whether the UE 110 supports non-PMI-PortIndication.

Alternatively, if, at 405, the UE 110 indicates that it supportscri-RI-CQI with non-PMI-PortIndication reporting, then, in someembodiments, at 410, the UE 110 may additionally report the maximumnumber of CSI-RS resources that can be configured. As a result, thenumber of entries for PortIndexFor8Ranks in the RRC configuration of thecri-RI-CQI with non-PMI-PortIndication is reduced from themaxNrofNZP-CSI-RS-ResourcesPerConfig (e.g., 128) to the UE reportedcapability (the maximum number of CSI-RS resources that can beconfigured), thus reducing the overhead at the UE 110.

At 415, the UE 110 reports the maximum number of multi-in multi-out(MIMO) layers (ranks) supported by the UE 110 for cri-RI-CQI reporting.In some embodiments, the maximum number of ports that the gNB 120 a canconfigure for each CSI-RS resource for the cri-RI-CQI report cannotexceed the maximum number of MIMO layers reported by the UE 110. The UE110 may also report the maximum number of ports that can be configuredper CSI-RS resource for the csi-RI-CQI measurement. For example, if theUE 110 reports that it supports a maximum of 4 MIMO layers, the gNB 120a cannot configure more than 4 CSI-RS ports for each CSI-RS resource forcri-RI-CQI reporting. In some embodiments, the gNB 120 a may onlyconfigures up to the maximum number of MIMO layers in thePortIndexFor8Ranks IE. For example, assuming again that the UE reportsthat it supports a maximum of 4 MIMO layers, then the gNB 120 a onlyconfigures up to rank 4, (e.g., rank1, rank2, rank3 and rank4) in thePortIndexFor8Ranks configuration. At 420, the UE 110 receives the CSIreport configuration for the cri-RI-CQI report from the gNB 120 a basedon the capabilities the UE 110 has reported.

FIGS. 5A-5C shows exemplary diagrams illustrating reception of CSIresources in the time domain according to various exemplary embodiments.Discontinuous reception (DRX) allows the UE 110 to save power byrepeatedly going into a sleep mode and subsequently an active mode,during which the UE 110 listens for any data sent from the gNB 120 a.For CSI purposes, the UE 110 receives the CSI resources (CMR 502 a,b andIMR 504 a,b) during the DRX active time periods 506 a,b. In someembodiments, to reduce overhead at the UE side, the gNB 120 a may notexpect the UE 110 to transmit a CSI report when the UE 110 receives aCMR 502 a in a first DRX active time period 506 a and an IMR 504 b in asecond DRX active time period 506 b, as illustrated in FIG. 5B. As notedabove, such a scenario requires the UE 110 to store the CMR (or IMRdepending on which resource is received first) measurements until itreceives the IMR 504 and performs the IMR measurements to complete theCSI report. By eliminating the need for the UE 110 to report the CSI inthis scenario, the overhead at the UE 110 associated with the storing ofthe measured CMR is eliminated. To achieve this, the gNB 120 a ensuresthat the CMR 502 a,b and IMR 504 a,b are always transmitted to the UE110 in the same DRX active time period 506 a,b.

In some embodiments, if the gNB 120 a transmits a first CMR 502 a and afirst IMR 504 a during a first DRX active time period 506 a and just asecond IMR 502 b during a second DRX active time 506 b, as illustratedin FIG. 5C, the UE 110 will only report the CSI for the measurementsperformed on the first CMR 502 a and the first IMR 504 a. This scenariomay exist when, for example, one of the resources (e.g., the IMR) is notreported during every DRX active time period because it has not changedor has minimally changed since the last time the resource was reported.

As noted above, when the gNB 120 a configures atwoTX-CodebookSubsetRestriction, as defined in 3GPP TS 38.214, and atypeI-SinglePanel-ri-Restriction, as defined in 3GPP TS 38.331, torestrict which precoding matrix indicator (PMI) can be selected by theUE 110 from the Rel-15 Type I Single Panel codebook defined in 3GPP TS38.214, a conflict may arise between these two restrictions. In someembodiments, the UE 110 may honor both restriction methods. For example,if a PMI is prohibited by either one of the restriction methods, thenthe UE 110 will not report that PMI. In some embodiments, the UE 110will alternatively ignore the typeI-SinglePanel-ri-Restriction. In someembodiments, the UE 110 will alternatively ignore thetwoTX-CodebookSubsetRestriction. In some embodiments, however, the gNB120 a will only configure one of these restrictions so that the conflictnever arises.

Those skilled in the art will understand that the above-describedexemplary embodiments may be implemented in any suitable software orhardware configuration or combination thereof. An exemplary hardwareplatform for implementing the exemplary embodiments may include, forexample, an Intel x86 based platform with compatible operating system, aWindows OS, a Mac platform and MAC OS, a mobile device having anoperating system such as iOS, Android, etc. In a further example, theexemplary embodiments of the above described method may be embodied as aprogram containing lines of code stored on a non-transitory computerreadable storage medium that, when compiled, may be executed on aprocessor or microprocessor.

Although this application described various aspects each havingdifferent features in various combinations, those skilled in the artwill understand that any of the features of one aspect may be combinedwith the features of the other aspects in any manner not specificallydisclaimed or which is not functionally or logically inconsistent withthe operation of the device or the stated functions of the disclosedaspects.

It is well understood that the use of personally identifiableinformation should follow privacy policies and practices that aregenerally recognized as meeting or exceeding industry or governmentalrequirements for maintaining the privacy of users. In particular,personally identifiable information data should be managed and handledso as to minimize risks of unintentional or unauthorized access or use,and the nature of authorized use should be clearly indicated to users.

It will be apparent to those skilled in the art that variousmodifications may be made in the present disclosure, without departingfrom the spirit or the scope of the disclosure. Thus, it is intendedthat the present disclosure cover modifications and variations of thisdisclosure provided they come within the scope of the appended claimsand their equivalent.

1. A processor configured to perform operations comprising: transmittingUE capabilities for channel state information (CSI) reporting to a basestation, wherein the UE capabilities include aCSI-RS-resource-indicator(CRI)-rank indicator(RI)-channel qualityindicator (CQI) reporting capability and a further CRI-RI-CQI reportingcapability; and receiving a CSI report configuration from the basestation, wherein the CSI report configuration is based on the UEcapabilities.
 2. The processor of claim 1, wherein the CRI-RI-CQIreporting capability indicates whether the UE supports CRI-RI-CQIreporting.
 3. The processor of claim 2, wherein when CRI-RI-CQIreporting capability indicates that the UE supports CRI-RI-CQI withnon-precoding matrix indicator(PMI)-PortIndication and the base stationis part of a first type of network, the processor is configured toreport that the UE supports CRI-RI-CQI reporting.
 4. The processor ofclaim 2, wherein when CRI-RI-CQI reporting capability indicates that theUE supports CRI-RI-CQI without non-precoding matrixindicator(PMI)-PortIndication and the base station is part of a firsttype of network, the processor is configured to report that the UE doesnot support CRI-RI-CQI reporting.
 5. The processor of claim 2, whereinwhen the CRI-RI-CQI reporting capability indicates the UE supportsCRI-RI-CQI reporting, the processor is configured to indicate whetherthe UE supports CRI-RI-CQI with non-precoding matrixindicator(PMI)-PortIndication or CRI-RI-CQI withoutnon-PMI-PortIndication.
 6. The processor of claim 5, wherein when theprocessor indicates that the UE supports CRI-RI-CQI with non-precodingmatrix indicator(PMI)-PortIndication, the processor further indicatesthat the UE also supports CRI-RI-CQI without non-precoding matrixindicator(PMI)-PortIndication.
 7. The processor of claim 5, wherein whenthe CRI-RI-CQI reporting capability indicates the UE supports CRI-RI-CQIwith non-PMI-PortIndication, the processor is configured to indicate amaximum number of CSI-RS resources that may be configured for theCRI-RI-CQI report.
 8. (canceled)
 9. The processor of claim 1, whereinthe CRI-RI-CQI reporting capability indicates a maximum number ofmulti-in multi-out (MIMO) layers for each CSI reference signal (CSI-RS)configured for a CRI-RI-CQI report.
 10. The processor of claim 9,wherein a maximum number of ports that may be configured for each CSI-RSresource for the CRI-RI-CQI report cannot exceed the maximum number ofMIMO layers.
 11. (canceled)
 12. The processor of claim 1, wherein theCSI report includes a PortIndexFor8Ranks information element (IE), andwherein the base station configures only up to the maximum number ofMIMO layers for the PortIndexFor8Ranks IE.
 13. A processor configured toperform operations comprising: entering a discontinuous reception (DRX)active time period; determining whether channel state information (CSI)resources were received during the DRX active time period; and when CSIresources were received during the DRX active time period, determiningwhether to perform CSI measurements during the DRX active time periodbased on the received CSI resources.
 14. The processor of claim 13,wherein the operations further comprise: when no CSI resources werereceived during the DRX active time period, omitting performing the CSImeasurements during the DRX active period.
 15. The processor of claim13, wherein, when the CSI resources comprise a channel measurementresource (CMR) and an interference measurement resource (IMR), the CSImeasurements are performed during the DRX active period based on the CMRand the IMR.
 16. The processor of claim 13, wherein, when the CSIresources comprise only one of a channel measurement resource (CMR) oran interference measurement resource (IMR), omitting performing the CSImeasurements during the DRX active period.
 17. A processor configured toperform operations comprising: receiving one of a first restriction froma base station regarding a precoding matrix indicator (PMI) codebookrank or a second restriction from the base station regarding one or morePMI codebook values; and reporting a PMI value to the base station basedon at least one of the first restriction or the second restriction. 18.The processor of claim 17, wherein the processor receives both the firstrestriction and the second restriction and the reported PMI valuesatisfies both the first restriction and the second restriction.
 19. Theprocessor of claim 17, wherein the processor receives both the firstrestriction and the second restriction and disregards the firstrestriction, wherein the reported PMI value satisfies only the secondrestriction.
 20. The processor of claim 17, wherein the processorreceives both the first restriction and the second restriction anddisregards the second restriction, wherein the reported PMI valuesatisfies only the first restriction.
 21. The processor of claim 17,wherein the processor receives only the first restriction, wherein thereported PMI value satisfies only the first restriction.
 22. Theprocessor of claim 17, wherein the processor receives only the secondrestriction, wherein the reported PMI value satisfies only the secondrestriction. 23-24. (canceled)